The Truckee River Biomass Monitoring (TRBM) program has collected data regarding algal biomass in the lower Truckee River [expressed as plant pigments (chlorophyll a), carbon, nitrogen and phosphorous] that can be used for independent analysis of ecosystem health and nutrient budgets. Furthermore, the biomass sampling program has been implemented in such a manner that the results will be used to validate water quality models and, hence, to make model formulations more scientifically defensible as management tools.

Data reported within this draft were generated as part of the second round of monthly biomass sampling that began in November 2001 and was completed as of August 2002.

The Study
In monitoring plant and algal biomass in the lower Truckee River we conducted the following field activities: Samples were collected four times at eleven sites (HERS, FLEI, PATA, EMCC, LOCK, PATR, TRAC, PAIN, JOHN, DEAD, LNIX) on the Truckee River (Figure 2) and an additional six times at eight of the eleven sites (HERS, FLEI, PATA, LOCK, PATR, TRAC, JOHN, LNIX). Sampling at all eleven sites was conducted on a quarterly basis to be consistent with the previous monitoring program (July 2000 to July 2001), which also included more spatially intensive sampling for increased spatial information on a quarterly basis. Eight of the eleven sites were sampled on a monthly basis. During the majority of sampling, temperature, pH, specific conductance, and dissolved oxygen were recorded in real-time using YSI Incorporated sondes provided by Washoe County. River velocity measurements were made at points where samples were collected to constrain the physical flow regime of the plant communities beyond levels previously attained.

Samples for water quality analysis were collected at each sampling site (consistent with monthly or quarterly sampling) using a depth-integrating sampler and were delivered to Truckee Meadows Water Reclamation Facility (TMWRF) for analysis. Vertical profiles of solar irradiance in the water column were conducted to constrain previously estimated light penetration values used for modeling primary productivity and in community metabolism studies.

At each site during each round of sampling, an average of 14 periphyton samples were collected for ash free dry weight (AFDW) and chlorophyll a. A minimum of three samples from each site were collected for determining periphyton functional groups (e.g. blue green algae, filamentous green algae, green algae, and diatoms) that are consistent with groupings currently used in water quality models (e.g. DSSAMt). On average, five subsamples of periphyton from each site were analyzed for carbon, nitrogen, and phosphorous contents.